docs: def make_allele_by_consequence(self, consequence, gene_id, gene_symbol):
          """
          Given a "consequence" label that describes a variation type,
          create an anonymous variant of the specified gene as an instance of
          that consequence type.
  
          :param consequence:
          :param gene_id:
          :param gene_symbol:
          :return: allele_id
          """
  
          allele_id = None
  
          # Loss of function : Nonsense, frame-shifting indel,
          #   essential splice site mutation, whole gene deletion or any other
          #   mutation where functional analysis demonstrates clear reduction
          #   or loss of function
          # All missense/in frame : Where all the mutations described in the data
          #   source are either missense or in frame deletions and there is no
          #   evidence favoring either loss-of-function, activating or
          #   dominant negative effect
          # Dominant negative : Mutation within one allele of a gene that creates
          #   a significantly greater deleterious effect on gene product
          #   function than a monoallelic loss of function mutation
          # Activating : Mutation, usually missense that results in
          #   a constitutive functional activation of the gene product
          # Increased gene dosage : Copy number variation that increases
          #   the functional dosage of the gene
          # Cis-regulatory or promotor mutation : Mutation in cis-regulatory
          #   elements that lies outwith the known transcription unit and
          #   promotor of the controlled gene
          # Uncertain : Where the exact nature of the mutation is unclear or
          #   not recorded
  
          type_id = self.resolve(consequence, mandatory=False)
          if type_id == consequence:
              LOG.warning("Consequence type unmapped: %s", str(consequence))
              type_id = self.globaltt['sequence_variant']
  
          # make the allele
          allele_id = ''.join((gene_id, type_id))
          allele_id = re.sub(r':', '', allele_id)
          allele_id = '_:'+allele_id  # make this a BNode
          allele_label = ' '.join((consequence, 'allele in', gene_symbol))
  
          self.model.addIndividualToGraph(allele_id, allele_label, type_id)
          self.geno.addAlleleOfGene(allele_id, gene_id)
  
          return allele_id